000 AXPZ20 KNHC 121006 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC WED FEB 12 2014 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0945 UTC. ...SPECIAL FEATURES... GULF OF TEHUANTEPEC...LATEST SURFACE ANALYSIS AND SATELLITE IMAGERY SHOW A COLD FRONT PUSHING SOUTHWARD ALONG THE EASTERN SLOPES SIERRA MADRE ORIENTAL MOUNTAINS. IN ITS WAKE...STRONG HIGH PRES IS SURGING SOUTHWARD ACROSS EASTERN AND SOUTHEASTERN MEXICO. THE RESULTANT TIGHT PRES GRADIENT IS FORECAST TO LEAD TO N TO NE 20-30 KT WINDS TO SEEP THROUGH THE CHIVELA PASS AND OUT ACROSS THE GULF THIS EVENING. THESE WINDS WILL QUICKLY INCREASE TO MINIMAL GALE STRENGTH LATE TONIGHT...BUT WILL WILL BE SHORT- LIVED AS THE CULPRIT HIGH PRES OVER S CENTRAL TEXAS AND NE MEXICO SHIFTS EASTWARD AND WEAKENS DURING THE THU. THE GALE FORCE WINDS ARE THEN FORECAST TO DIMINISH TO 25-30 KT THU AFTERNOON...AND TO 20-25 KT THU NIGHT. SEAS ARE FORECAST TO MAX OUT TO 12 FT AT TIME OF THE GALE EVENT...AND INTO THU. SEAS SUBSIDE TO 9 FT BY LATE THU NIGHT...WITH RESIDUAL 8 FT SEAS IN MIXED NE AND SW SWELLS ELSWHERE WITHIN 60 NM OF A LINE FROM 16N95W TO 13.5N95W AT THAT TIME. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS SW FROM THE COAST OF COSTA RICA AT 10N84W TO 08N912 WHERE SCATTEROMETER WINDS INDICATE A TRANSITION TO THE ITCZ AXIS. THIS AXIS CONTINUES TO 06N104W TO 07N118W TO 07N130W TO 06N140W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 75 NM N OF THE AXIS BETWEEN 118W- 123W. SCATTERED MODERATE CONVECTION IS WITHIN 30 NM OF A LINE FROM 09N125W TO 09N129W. ...DISCUSSION... A LARGE UPPER LEVEL TROUGH EXTENDS FROM THE CENTRAL U.S. SW ACROSS CENTRAL MEXICO TO A BASE NEAR 21N106W. TO THE SW OF THE TROUGH...A CUT-OFF LOW MOVING W IS LOCATED AT 17N131W WITH A TROUGH SSW TO 10N135W TO 06N136W. A MID/UPPER SHORTWAVE RIDGE IS TO THE NE AND E OF THE LOW AND TROUGH. A JET STREAM BRANCH IS TO THE SE OF THE LOW ALONG A POSITION FROM 08N133W TO 15N125W...AND ROUNDS THE BASE OF UPPER TROUGH OVER THE FAR EASTERN PART OF THE AREA. VERY PRONOUNCED SWLY FLOW ALONG AND TO THE S OF THE JET IS TRANSPORTING AMPLE DEEP LAYER MOISTURE FROM THE DEEP TROPICS ...IN THE FORM OF DENSE MAINLY MID TO HIGH CLOUDS...NEWD TO NEAR 119W WHERE IT THINS OUT TO SCATTERED TO BROKEN HIGH CLOUDS THAT ARE ADVECTED FURTHER EASTWARD TO ACROSS CENTRAL MEXICO. THIS MOISTURE IS BEING FURTHER AIDED BY UPPER DEBRIS CLOUDS FROM DEEP CONVECTION ALONG AND NEAR THE ITCZ AXIS AS DESCRIBED ABOVE. AN UPPER DIFFLUENT FLOW PATTERN TO THE E OF THE LOW RELATED TO THE REAR RIGHT QUADRANT OF THE JET STREAM BRANCH IS HELPING TO SUSTAIN THE AFOREMENTIONED ITCZ RELATED CONVECTION. OVER THE FAR EASTERN PORTION OF THE AREA E OF ABOUT 100W...A BROAD UPPER RIDGE IS SEEN EXTENDING FROM AN ANTICYCLONE SITUATED OVER WESTERN COLOMBIA SW TO THE VICINITY OF THE GALAPAGOS ISLANDS. A MID/UPPER LEVEL TROUGH IS ROUGHLY ALONG 108W FROM 05N TO 16N. UPPER DIFFLUENCE BETWEEN THIS TROUGH AND THE RIDGE CONTINUES TO AID SCATTERED TSTMS IN SMALL CLUSTERS TO THE S OF THE MONSOON TROUGH FROM 03N TO 07N E OF 90W. ADDITIONAL MOISTURE OVER THIS AREA IS BEING PROVIDED FROM UPPER LEVEL DEBRIS CLOUDINESS DERIVED FROM CONVECTION OVER S AMERICA. THE RIDGE AXIS IS FORECAST TO SHIFT N TO NEAR 07N BY LATE FRI. THIS SHOULD INCREASE THE MOISTURE CONTENT OF THE ATMOSPHERE NEAR THE COAST ALONG WITH INCREASING CHANCES FOR SHOWER AND TSTM ACTIVITY. ELSEWHERE OVER THE EASTERN PORTION...CONVECTION REMAINS SUPPRESSED UNDER VERY DRY AIR ALOFT ASSOCIATED WITH THE UPPER RIDGE. ONLY ISOLATED SHOWERS AND WEAK ISOLATED TSTMS EXIST ACROSS THIS PORTION OF THE AREA. AT THE SURFACE...HIGH PRES OF 1026 MB IS ANALYZED AT 32N127W WITH A RIDGE EXTENDING SE TO 25N124W TO NEAR 19N118W. ANOTHER RIDGE EXTENDS SW FROM THE HIGH CENTER TO W OF THE AREA AT 27N140W. A TIGHT PRES GRADIENT TO THE SW OF THE FIRST RIDGE IS MAINTAINING AN AREA OF NE TO E 20-25 KT TRADES FROM 08N-20N W OF 128W WITH SEAS 8-10 FT. THESE TRADES WILL DIMINISH...AND THE AREAL COVERAGE WILL SHRINK AS WELL THROUGH FRI IN RESPONSE TO WEAKENING OF THE 1026 MB HIGH. GLOBAL MODELS SUGGEST THAT WEAK LOW PRES OR A TROUGH MAY FORM OVER THE FAR EASTERN PORTION OF THE AREA THU AND FRI TO THE SW OF COSTA RICA NEAR 07N88W WITH WEAK SW FLOW TO ITS S. GULF OF PAPAGAYO...THE NEXT PULSE OF NE 20-25 KT WINDS IS EXPECTED ON FRI. THE MATERIALIZATION OF THESE WINDS MAY BE AIDED FURTHER BY THE DEVELOPMENT OF THE ABOVE MENTIONED WEAK LOW PRES OVER THE FAR EASTERN PORTION. $$ AGUIRRE